function checkAll(){
    var atribut = document.getElementsByClassName("atribut");
    for (var i=0; i<atribut.length; i++){
        atribut[i].checked = true;
    }
}

function uncheckAll(){
    var atribut = document.getElementsByClassName("atribut");
    for (var i=0; i<atribut.length; i++){
        atribut[i].checked = false;
    }
}